Modern tires are generally made of synthetic rubber, natural rubber, fabric and wire, along with other materials and/or fillers that reinforce the rubber. Tires consist of a tread and a body. The tread provides traction while the body ensures support. The majority of tires are pneumatic inflatable structures, including a doughnut-shaped body of cords and wires encased in rubber and generally filled with compressed air to form an inflatable cushion. Pneumatic tires are used on many types of vehicles, such as cars, bicycles, motorcycles, trucks, earthmovers, and aircraft.
Carbon black is a by-product produced by the incomplete combustion of heavy petroleum products such as fluid catalytic cracking (FCC) tar, coal tar, ethylene cracking tar, and a small amount from vegetable oil. Carbon black is a form of amorphous carbon that has a relatively high surface-area-to-volume ratio. Carbon black is used as a filler in plastic and rubber, principally pigment and reinforcement properties, particularly as a reinforcing filler in rubber products, especially tires. While a pure gum vulcanizate of styrene-butadiene (synthetic rubber) has a tensile strength on the order of up to 2.5 megapascals (MPa), it has very little abrasion resistance. Compounding the vulcanizate with carbon black improves its tensile strength and wear resistance. Over five million metric tons of carbon black is used each year in the tire industry with a typical tire containing between 30 to 35 percent carbon black. Carbon black is also used in other automotive products (e.g., belts, hoses), in the Aerospace industry in elastomers for aircraft vibration control components such as engine mounts, and in various other plastic products.
Lignin is a biopolymer found in woody plants. Lignin may be defined as an amorphous, polyphenolic material produced from enzymatic dehydrogenative polymerization of generally three principal phenylpropanoid monomers: (1) p-coumaryl alcohol, (2) coniferyl alcohol and (3) sinapyl alcohol.

An example of the polycondensation of coniferyl alcohol (2) is:

Lignin is produced generally as a by-product in wood processing. For example, lignin is typically required to be removed from wood pulp when the wood pulp is used for papermaking.
In practice, lignin may be recovered from wood pulp by various processes and thus, the nature of an individual lignin depends somewhat upon its plant of origin and recovery process. Examples of lignin recovery processes include by solvent extraction from wood meal, (e.g., “native lignin” or “Brauns lignin”); by cellulolytic enzyme treatment of finely ground wood meal followed by solvent extraction (e.g., cellulolytic enzyme lignin); by treatment of woody material with dioxane/dilute HCl (e.g., dioxane acidolysis lignin); by solvent extraction and purification of finely ground wood meal (e.g., milled wood lignin); by strong acid degradation of woody materials (e.g., Klason lignin); by successive treatments of woody material with sodium periodate followed by boiling water (e.g., periodate lignin); by reaction with sodium hydroxide and Na2S at an elevated temperature followed by isolation through acidification or ultrafiltration (e.g., Kraft lignin); and by reaction with sulfur dioxide and metal bisulfite in an acidic medium and at an elevated temperature (e.g., lignosulfonates). In a lignosulfonate process, lignin is made soluble by sulfonation at benzyl alcohol, benzyl aryl ether and benzyl ether linkages of phenyl propane units. Lignosulfonates may then be isolated by the addition of a base such as sodium hydroxide, magnesium hydroxide, calcium hydroxide and ammonia. Lignosulfonates have been proposed for use as a filler for tires and as a substitute for carbon black.